Lithography machines are known in the prior art in which patterns and structures may be applied to surfaces by way of exposure of materials (for example, exposure using a particle beam).
For such a lithography machine, a particle-beam deflection device is known in the prior art which is situated in the beam path of a lithography machine designed as a particle beam apparatus. In this prior-art particle beam apparatus, an electron beam is generated by an electron source, focused by lenses, and guided to an object. A blanking aperture and a deflection unit are situated in the beam path of the electron beam. This prior-art deflection unit has a plate-shaped design and combines magnetic deflection with electrostatic deflection. The purpose of the aforementioned prior art is to blank out the electron beam, so that parts of the object are not exposed during lithography.
Furthermore, it is known from the prior art that an electron beam is blanked with the aid of a blanking unit made up of two pairs of plates, positioned one on top of the other, and an aperture in between them.
With regard to the above-indicated prior art, reference is made to U.S. Pat. No. 4,434,371 as well as the dissertation of Dr. Martin Müller, “Abstimmbare Halbleiterlaser and schmalbandige Laserarrays mit verteilter lateraler Rückkopplung” (Tunable semiconductor lasers and narrow-band laser arrays with distributed lateral feedback), Würzburg 2003, pages 30-31.
The above-indicated combination of magnetic and electrostatic deflection units, however, is a quite complicated design and requires higher effort for controlling the electrostatic and magnetic deflection unit with regard to their tuning.
Furthermore, it is known from the prior art to provide a particle beam apparatus, equipped with a condenser lens and an objective lens, with a deflection device that has at least one pair of deflector plates or at least one pair of deflector coils. Thus the deflection device is situated between the condenser lens and the objective lens at a position on the beam axis of the particle beam apparatus. If two pairs of deflector plates are provided, then according to the prior art these are situated in series between the condenser lens and the objective lens (i.e., in the order condenser lens—pair of deflector plates—pair of deflector plates—objective lens) along the beam axis of the particle beam apparatus. With these prior-art deflection devices, deflection of a particle beam is indeed possible; however, in this prior art, drift of the particle beam is quite likely. Drift of the particle beam is understood to mean movement of the impact point of the particle beam on the sample (or other object) after a deflection. After the deflection, the particle beam thus does not stay at the spot or does not stay in a very restricted region, but rather moves and thus may strike areas of a sample that should not really be exposed. This drift is particularly disadvantageous because small structures very close to each other may easily be damaged by this drift. This disadvantage is in particular a consequence of the required rapid control of the pair of deflector plates. Because of time delays in the control electronics, often it is not possible to precisely and rapidly control the pair or pairs of deflector plates in such a way that a sufficiently reliable deflection is assured. The positioning of the pairs of deflector plates relative to each other must also be very exact, so that a particle beam is no longer unintentionally moved after its deflection. This exact positioning could be implemented only at very high effort.
Another prior art is depicted in FIG. 1. FIG. 1 shows a prior-art particle beam apparatus in the form of a lithography machine having a deflection device for deflecting a particle beam. The prior-art particle beam apparatus has a beam source 1 which generates a particle beam 2. Particle beam 2 is guided to an object 3 with a suitable lens configuration (condenser, objective, not shown in FIG. 1) along a beam axis 8, which corresponds to the optical axis of the prior-art particle beam apparatus. Particle beam 2 may be deflected away from beam axis 8 with the aid of two crossed pairs of deflector plates, namely a first pair of deflector plates 4a,4b and a second pair of deflector plates 5a,5b, which form the deflection device. A voltage V1 is applied to the first pair of deflector plates 4a,4b by a first voltage supply unit 6, while a voltage V2 is applied to the second pair of deflector plates 5a,5b by a second voltage supply unit 7. A particular deflection of particle beam 2 from beam axis 8 is set by suitably selecting the ratio of voltages V1 and V2. Thus particle beam 2 is deflected in such a way that it is directed on object 3 in a direction in which additional exposure is not a problem, until the beam strikes blanking aperture 9 and thus is no longer directed to object 3. In many particle beam apparatuses, however, the available installation space is very limited, so often several pairs of deflector plates cannot be positioned simultaneously in one place in the same particle beam apparatus. Furthermore, because of signal delay times and stray capacitances in the voltage supply units, a particular ratio of voltages V1 and V2 might not always be ensured, so that a desired deflection of the particle beam is not achieved.
Therefore it would be desirable to provide a device for deflecting or guiding in a particle beam for a particle beam apparatus which has a simple design, requires little installation space, and furthermore ensures that no area of an object is exposed by a particle beam which is not supposed to be exposed.